Monte Carlo Simulation of Electron and Photon Transport The EGS (Electron–Gamma–Shower) system of computer codes is a general purpose pack age for the Monte Carlo simulation of the coupled transport of electrons and photons in an arbitrary geometry for particles with energies above a few keV up to several hundreds of GeV. This report introduces a new, enhanced version called EGSnrc. In addition to explaining and documenting the various enhancements and changes to the ...